A few days ago, a few crocodile gars made people panic, adults and children changed their color when they heard it. Relevant personnel acted quickly, took measures, and strived to eliminate evil.
On August 26, in Yunchan Lake, Ruzhou City, Henan Province, a crocodile gar was caught; on August 27, two crocodile gars were caught in the artificial lake in a small area of Qingdao West Coast New Area... Someone Statistics show that in the past six months, traces of alligator gar have been found in 12 provinces and cities in my country, and at least 19 alligator gar have been caught.
The alligator gar is a large carnivorous fish with sharp teeth and a ferocious nature. It preys on creatures in the water, especially fish in the water. Some experts say that a crocodile gar can eat up all the fish in the water, and even endanger the personal safety of nearby residents and tourists.
There was no alligator gar in our country, it is an alien species.
In nature, alien species that harm and attack humans are rare, but there are many species of alien species that cause serious harm to my country's ecological environment.
Alligator Gar.
Alligator Gar. (Source: People's Daily )
01
The madness concealed by the beautiful appearance
My understanding of alien species began more than 40 years ago. There are three "bays" in the village where
's hometown is located. The so-called "bay", also known as a pond, is a depression in which water is stored. There is water in all seasons, especially in the rainy season, the rainwater gathers here, and the bay is full of water.
However, except for the cold winter, the water is covered with a thick or thin layer of ice, and there is nothing else in the bay, which is very monotonous.
One day in the 1970s, the villagers discovered that a green plant suddenly appeared in the bay at the east end of the village. It floats on the water, the leaves are green and thick, the surface is smooth, the petioles are hollow, and there is an air sac in the lower part, which is in the shape of a gourd. The village official responsible for introducing the plant said it was called water hyacinth. After a few days, the water hyacinth bloomed, lavender, and it was really beautiful. The arrival of
water hyacinth has brought vitality to the monotonous water surface. Usually, the villagers can watch the leaves, their eyes are full of green, and they can enjoy the gorgeous flowers during the flowering season.
At the beginning, there were only a few water hyacinths in the bay. Later, it quickly multiplied, and the number gradually increased, and it developed to a dozen, dozens of trees... and finally covered the entire water surface.
When the number of water hyacinths was small, the village demanded that everyone could not take it from the bay without permission. Later, when there were too many water hyacinths, the village sent people to fish them out of the bay and used them to make green manure, and some villagers took them home to feed the pigs.
Several years later, I learned that this water hyacinth, also called water hyacinth , is an invasive plant. Native to the Amazon basin of South America, it is a perennial aquatic plant. There was no water hyacinth in our country. In 1901, as an ornamental plant, water hyacinth was introduced to China. Under the cover of their beautiful appearance - green leaves and purple flowers, they multiply wildly in waters all over our country, and their descendants increase uncontrollably, occupying bays and ponds, covering rivers and lakes, resulting in a large number of aquatic organisms due to lack of oxygen and air pollution. Insufficient sunlight causes death and destroys the ecological balance in the water, which has become a major scourge.
has a beautiful looking water hyacinth.
American white moth , is also a typical invasive alien species.
White moth is native to North America . During World War II, it traveled across the ocean with military supplies and spread to Europe. It was first discovered in Hungary in 1940, and then spread to most of Europe except northern Europe. In 1945, the American white moth landed in Tokyo, Japan with military supplies, and reached Asia for the first time, then arrived in South Korea, and then went all the way north into North Korea. In 1979, the American white moth appeared in the Dandong area of Liaoning Province, officially announcing its invasion of China.
The American white moth is a greedy foodie with a large appetite and not a picky eater. All crops, weeds, broad-leaved trees, shrubs, and even gymnosperms are delicious meals in its eyes. According to incomplete statistics, there are 636 species of host plants in the world. Among them, there are 120 species in the United States, more than 300 species in Japan, 234 species in Europe, and 94 species in Dandong, Liaoning, China alone.
When the white moth eats plants, it usually fights in groups. Several larvae before the fifth instar first cover a large forest, weave a net, and then gather in the net.In the middle of the day, start a dinner party, "chachacha—" they feed on leaves day and night. After eating the leaves or other plants in one place, they migrate to the next place. Wherever they pass, they often leave no leaves behind. The severely damaged place looked as if it had been burned by a fire. Another terrifying feature of the
American white moth is that it reproduces amazingly. A female moth lays 800 to 2,000 eggs at a time, reproduces three generations a year, and can reproduce 200 million larvae a year. In other words, even if only one female moth slips through the net during the prevention and control, after one year, it may reproduce 200 million offspring! This undoubtedly brings great difficulty to the prevention and control work.
The American white moth, which was first discovered in northeastern my country, gradually moved south to conquer the city. So far, they have invaded and ravaged 13 provinces including Jilin, Liaoning, Beijing, Tianjin, Hebei, Inner Mongolia, Shaanxi, Henan, Shandong, Jiangsu, Shanghai, Anhui, and Hubei.
In addition to the above water hyacinth, American white moth, Spartina , Spartina alterniflora , Elastane , Solidago , Pine wood nematode , Spodoptera frugiperda , RIFA , Fushou snail , etc. are also invasive alien species that cause great harm to my country's ecological environment. According to statistics, more than 660 invasive alien species have been discovered in my country so far, and the economic loss caused by their invasion is as high as more than 200 billion yuan every year.
02
Alien species have beneficial species
Are all exotic species harmful?
is not, there are also many exotic species that are beneficial to human beings, such as vannamei , dragon fruit .
Now, the farming, sales and consumption of Penaeus vannamei have become a major industry in my country. As can be seen from the name, it is native to South America and is mainly distributed in the Pacific coastal waters of the western United States. There are members of their family from the Gulf of Mexico to the central part of Peru.
The first time I saw a Penaeus vannamei farming pond was in a town in the vast northern Shandong Plain. The local farmers dug ponds on the saline-alkali land and put in shrimp seedlings. At first, only a few households raised them, and the scale was not too large. Later, with the success of their farming, the town government issued policies to support them in a timely manner, and other farmers scrambled to keep up and gradually expanded the scale of farming. Today, the town has become a big farming town for Penaeus vannamei.
Our country introduced Penaeus vannamei in the late 1980s, and in the early 1990s, researchers succeeded in artificially breeding Penaeus vannamei. After 2000, from the east to the west, from the coast to the inland, large-scale farming began in various places. Today, about two-thirds of the shrimp cultured in marine waters in my country belong to Penaeus vannamei, with an annual output of about 400,000 tons.
Penaeus vannamei, the introduction of this exotic species, has promoted economic development, enriched a number of farmers and distributors, and enriched the dining tables of urban and rural residents.
dragon fruit.
Dragon fruit of the cactus family , originating in Central America Costa Rica , Guatemala , Panama, Ecuador , Cuba , Colombia and other places. Later, it was introduced to Southeast Asian countries such as Vietnam and Thailand, as well as Taiwan, as well as Hainan, Guangxi, Guangdong, Fujian, Yunnan and other provinces.
Nowadays, dragon fruit is not only the favorite fruit of southern residents, but also children and adults living in the north often go to the market and store to buy dragon fruit, a real treat.
Dragon fruit is sweet and nutritious. In particular, it should be pointed out that the sugars contained in its pulp are mainly glucose , which are easily absorbed by the human body and are suitable for consumption after exercise when energy substances are urgently needed. Dragon fruit also contains a high concentration of natural pigment anthocyanin , anthocyanin is an anti-aging substance, so regular consumption of dragon fruit can prolong life. Dragon fruit contains the meaning of auspiciousness, health, wealth and longevity. In the folk, people often place a dragon fruit in the fruit basket they carry to bless each other whether they are visiting relatives and friends or visiting patients.
Sweet potato, as one of the main food crops in our country, has saved many lives in famine years, it is an alien species.
sweet potato is native to ChinaSouth America's , Mexico's , and Colombia. After Columbus discovered the New World in 1492, it gradually spread to Europe and Southeast Asia, and was introduced to my country at the end of the 16th century. There are many channels for the introduction of sweet potatoes in my country. Among them, the most talked about among the people is that in the 21st year of Wanli in the Ming Dynasty (1593), the Chinese Chen Zhenlong brought a few from Luzon (now the Philippines). sweet potato seedlings , returned to their hometown, Changle, Fujian for trial planting. In the second year, his son Chen Jinglun reported to Jin Xuezeng, the governor of Fujian, and received strong support from Jin Xuezeng, instructing to "try the seeds according to the law". As a result, sweet potatoes have been popularized in Fujian for a few years. Later, it was gradually promoted to the Yangtze River Basin, North China and other places. It is worth mentioning that from the 14th to the 19th year of Qianlong in the Qing Dynasty, Chen Shiyuan, the great-grandson of Chen Jinglun, came to Jiaozhou, Shandong, and gradually experimented and explored and taught farmers how to store sweet potato for winter, laying a solid foundation for the widespread promotion of sweet potato planting in the local area. Good foundation.
Sweet potato has wide adaptability, simple and easy-to-learn cultivation methods, and high yield. During the famine years, many people had to rely on sweet potatoes to survive the difficult years.
Sweet potato, Shandong called sweet potato. I remember that when I was a child, the staple food was sweet potatoes, supplemented by a small amount of corn cakes or wofutou. In autumn, when the sweet potatoes were just harvested, my mother brought some, washed the mud, put them in a large pot, poured water over the sweet potatoes, and cooked them on fire. This is the family's food. Fresh sweet potatoes are easy to rot, so except for a small part stored in wells, most of them are cut into slices, put in the ground to dry, made dried sweet potatoes , and stored. When the rest of the grain is eaten, take out some to cook to satisfy hunger.
Dried sweet potatoes taste a bit bitter and taste bad, but without it, some people might starve to death in times of famine.
sweet potato (sweet potato). Our common crops, such as corn, peanuts and other field crops, cucumbers, peppers, eggplants, onions, garlic, spinach, potatoes, tomatoes, carrots and other vegetables, grapes, strawberries, mangoes and other fruits, and Forage grasses such as alfalfa are also beneficial exotic species.
can say that without exotic species, our rice bags, vegetable baskets and fruit plates would not be so colorful today.
03
Scientific prevention of invasive alien species
The difference between beneficial and harmful alien species is judged by human beings from their own standpoint.
If an alien species can be used, including food and use, to promote economic development, it is regarded as beneficial; on the contrary, if an alien species breaks the ecological balance of the introduced area, threatens the normal survival of humans or other organisms, affects economic development, and causes harm, it is considered beneficial. considered harmful.
Alien species reproduce recklessly, occupy land, block rivers, and cause flooding, often because there is no natural enemy restraint. In nature, any species is on one or more food chains. It is the food of lower-level creatures or non-living creatures, and is also eaten by higher-level creatures. For example, in the food chain of "green grass-rabbit-wolf", the herbivorous rabbit eats grass, and the carnivore wolf hunts the rabbit for food. Grass, rabbits, and wolves restrict each other, and the number is in a dynamic balance, which is called ecological balance.
If wolves suddenly become extinct, and rabbits are not restricted by their natural enemies, wolves, they will multiply rapidly, their numbers will increase greatly, they will eat grass, destroy the original ecosystem, break the ecological balance, and cause ecological disasters.
is in the hometown of and of the American white moth. For many years, the American white moth has been living in "harmonious" with other creatures without causing obvious harm. The main reason is that there are more than 50 kinds of parasitic natural enemy insects, 34 kinds of predatory organisms and many microorganisms. Pathogens effectively restrain it.
However, after the American white moth invaded China, the situation changed abruptly: the native natural enemies could not fully adapt to this pest, and the restriction effect was very small. As a result, the American white moth proliferated uncontrollably, feeding on the leaves of trees and crops, causing great harm in just a few years.
American white moth. (Image source: Xinhua News Agency)
A tree attacked by the American white moth.
A few years ago, when white moths were rampant and flooding in the United States, machines were sprayed with chemical pesticides to kill them, and personnel were mobilized into fields and villages.arrest, but the effect is not very obvious. Later, researchers began to look for 's natural enemy, , to control the insects.
The chief scientist of of the Chinese Academy of Forestry Sciences, Yang Zhongqi , led the team to go deep into the hardest-hit areas of the American white moth in various parts of my country to investigate and study. After more than ten years of exploration, Yang Zhongqi found that in China, the American white moth has 32 natural enemies, including 12 new species. He screened out an insect named " Zhou's rodent wasp ". This insect is parasitic in the body of the American white moth, and it is the dominant natural enemy of the American white moth in the native natural environment of our country, and at the same time does not pose a threat to the survival and reproduction of other insects. I once saw in a park in Jinan City, the Zhou's little bee card hanging on the branch by the plant protection personnel. In this way, relying on the little bees hatched from the bee card, the reproduction of the surrounding American white moth can be restricted to avoid harm.
This is a biological control measure that has to be taken after the invasion of alien species.
To prevent invasive alien species, we should also start from the source. The customs and quarantine department must strictly control the quarantine. For individuals, it is necessary to raise the awareness of protecting biodiversity, do not buy or release animals and plants at will, and be the guardian of ecological civilization.
Mass Newspaper Industry Rural Mass Reporter Chen Jianzhi
Review of past issues, click to read:
Agricultural Science Window (1) | What is the value of " sea rice "? Let's take a look at the Shandong practice of saline-alkali-tolerant rice breeding
Agricultural Science Window (2) | A weed and wheat were successfully hybridized, why did they win the praise of academicians?
Agricultural Science Window (3)|In addition to the melons bred by "grandma melon" Wu Mingzhu Academician, which melons have you eaten?
Agricultural Science Window (4)|African watermelon, the fruit is all over China, and the radiation of Shandong facility cultivation technology National
Agricultural Science Window (5) | A small wormwood has become a big industry
Agricultural Science Window (6) | Hybrid potatoes come out! Revealing the innovation story behind the secrets
Agricultural Science Window (7) | Click the magic "scissors", the world's first scented corn came out in Shandong
Agricultural Science Window (8) | A result changes an industry, from the direct harvest of the field to the compact corn
Agricultural Science Window (9) | Implementing "Bypass Surgery", Old Trees Rejuvenated …Where is the “special” variety of special-purpose wheat?
Agricultural Science Window (12) | Why a soybean touches the nerves of the Chinese people, and talks about the past and present of soybeans Science Window (14) | What can make popcorn is not ordinary corn kernels
Agricultural Science Window (15) | How difficult is it to build a robot to pick apples, and a brief history of robots
Agricultural Science Window (16) | " I saw a hedgehog hibernating in the ground!" Insect season talk about hibernation
Agricultural Science Window (17) | National soybean high-yield competition, how much per mu can win the championship?
Agricultural Science Window (18) | The earliest poultry, was it chicken, duck, or goose?
Agricultural Science Window (19) | Equinox wheat gets up and is worth a moment of gold
Agricultural Science Window (20) | Vegetables growing on trees
Agricultural Science Window (21) | Self-report of a soybean: Don’t be afraid of smashing your body, keep the essence In the world
Agricultural Science Window (22) | Uncovering the Mystery of Salt-Alkali-tolerant Plants High-tech
Agricultural Science Window (25) | Why Tomatoes Lost Their Old Taste
Agricultural Science Window (26) | No rain for 4 months, honeysuckle is flourishing? Look at its
Agricultural Science Window (27) to protect moisture and drought resistance
Agricultural Science Window (28) | Can goats and sheep be crossbred to produce lambs?
Agricultural Science Window (29) | Chickens living on tree branches - Talking about the familiar and unfamiliar chicken family (Part 1)
Agricultural Science Window ( 30) | Why was this achievement selected as one of the "Top Ten Events in China's Seed Industry"” ——On the past and present of chicken (Part 2)
